Breathing apparatus



juy 279 R943 H. H. FRYE ETAL 2325594 BREATHING APPARATUS Filed Feb. 27, 1942 3 Sheets-Sheet l INvEuroRs A HEY 27 11943@ H. H. FRYE ET AL. 2932,94

BREATHING APPARATUS l 5 Sheets-Shea?l 2 Filed Feb. 27, 1942 -vaY ATTORNEY my 27 i943@ H. H. FRYE E1- AL BREATHING APPARATUS 3 sheets-sheet s Filed Feb. 27, 1942 INVENTQRS Ufff@ ATTORNEY Patented July 27, 1943 BREATHING APPARATUS Henry H. Frye and'Albert R.'Behnke, United States Navy Application February 27, 1942, Serial No. 432,616

2 claims. (ci. 12s-191) (Granted under the act of March s, 1883,' as amended April so, 192s; 31o o. G. v51) This invention relates to a. breathing apparatus or respirometer, and has for an object to provide an improved breathing apparatus especially intended for supplying oxygen as needed, espe- -cially by a person in a location where the normal oxygen Supply in the atmosphere is unavailable. A further object of this invention is to provide a breathing apparatus especially intended for use by an aviator at high altitudes, which apparatus is capable oi supplying all the necessary oxygen for the aviator without needing attention for long periods of time, and which remains in good, operative condition under conditions of extremely low temperature and low pressure such as are customary in high iiight.

A further object of this invention is to provide a breathing apparatus in which the aviator or other person using the same is supplied with a constant amount oi moist warm oxygen, as needed. l

A further object oi' this inv/ention is to provide a breathing apparatus wherein the exhaled carbon dioxide is absorbed and as it is absorbed, reacts to provide sufcient heat to the fresh supply of engen to maintain it in a warm, moist and usable condition without danger of freezing, even though the atmospheric temperature were far below the usual freezing point.

A further object of this invention is to provide a breathing apparatus requiring the minimum of attention to place it in operation and requiringno attention to maintain it in operation except when extreme exertion on the part of the user may necessitate an increase in the oxygen supply, in which case a single manual motion is all that is necessary.

A further object oi' this invention is to provide a breathing apparatus in which an excess amount of oxygen is supplied and rebreathed and serves to rinse out the nitrogen in the closed system provided by the apparatus.

Still a further object of this invention is to provide a breathing apparatus which includes a replaceable purifying chemical canister and which, when desired, can be utilized without the presence of the canister as an open system.

With the foregoing and other objects in view,

the invention consists in the construction, cornparatus oi' this invention, partly in section and partly broken away.

Fig. 2 is a front elevatiorrof Fig. 1, the iiexible hose having been omitted.

Fig. 3 is a sectional view on line 3-3 of Fig. 1, the replaceable carton being shown in elevation.

Fig. 4 is a partly sectional and partly diagrammatic side elevation of the apparatus in operation, the breathing bag housing being omitted.

Fig. 5 is a iront elevation oi the breathing mask.

Fig. 6 is a view similar to Fig. 4, but used as an open system. i

Fig. 7 is a diagrammatic view similar to Figs. 4

v and 6, of a slightly modiiled form.

Figs. 8 and 8a are sectional views of check valves used in the form shown in Fig. 7.

Fig. 9 is a longitudinal sectional view of the' regulating air intake valve shown in Fig. 6.

Fig. 10 is a front elevational view of the intake valve of Fig. 9.

Fig. 11 is a sectional view of the blow-ofi valve for the container, being on line II-II of Fig. 12.

Fig. 12 is a top plan view of the blow-oil. valve.

Fig. 13 is a sectional view on line I3-I3 of Fig. 11.

Fig. 14 is a plan view of the plate and tension spring of the blow-01T valve.

Fig. 15 is a top plan view of the oxygen by-pass valve.

Fig. 16 is a sectional view on line IG-IB of Fig. 3.

Fig. 17 is a detail top plan view, partly in section, of the front end of the canister.

Fig. 18 is a detail view, partly in section, of the canister latch, and;

Fig. 19 is an enlarged elevational view of the latch.

There is shown at I0 in Fig. 4 the breathing apparatus of this invention, the housing for the breathing bag or reservoir II, however, being omitted from this gure and being shown at I2 in Figs. 1, 2 and 3. The entire breathing apparatus I 0 includes a face mask I3, secured in position by head straps I4 over the face I5 and head I6 of the aviator or other person using this apparatus.

Attached to the mask I3 is a flexible expiratory tube I1 detachably connected by bayonet joint I8 to a canister 20. The other end of the canister 20 is connected by a T-pipe 2l to the breathing bag or reservoir I I at one side and to a manually controllable oxygen regulator 22 at the other end. An oxygen bottle 23 is connected to the regulator in the customary manner by a cut-ofi valve 24. Extending through the oxygen regulator 22 is a manually controllable valve 25 for adjusting the :Iiow of oxygen from the bottle 23 through the regulator 22. A pressure gauge 25 on the bottle side of the valve 25 shows the pressure of the oxygen still in bottle 23, while another pressure gauge 21 on the other side of the valve 25 shows the pressure of the oxygen :lowing to the T-pipe 2|. Between the regulator 22 and the T-pipe 2| there is provided an oxygen by-pass valve 28, shown more in detail in Figs. and 16. This by-pass valve 28 is a three-way valve for connecting the regulator 22 either to the pipe 2| or to a by-pass conduit 29 which by-passes the T-pipe 2| and reservoir II to the reservoir outlet 30. A exible inspiratory tube 3I connects reservoir outlet 38 to the face mask I3.

'I'he canister 28 is adapted to contain a removable cartridge 32 containing a carbon dioxide absorbent 33 such as potassium hydroxide in shell form, commercially known as Shell Natrion." As will be observed, this cartridge 3| also has a screen 34 at each end thereof for holding the carbon dioxide absorbent therewithin, the screen, in turn, being held in position by a spider 35, while a tab 36 makes it easy to remove and replace the cartridge when necessary from the canister after releasing the latch 31 from the hinged door 38. 'I'he latch 31, shown in detail in Figs. 17, 18 and 19, is provided with a spring hinge 40 tending to hold it in the full line position shown in Fig. 18, preventing the cartridge 32 from accidentally dropping out while the door 38 is open. The latch 31 is provided with a bell-hangar shaped latch tooth 4I and finger ring 42 for opening the same when necessary,

The top'of the canister 20 is provided with a blow-oil valve 43. This blow-olf valve 43, shown in cross-section in Fig. 3 and in more detail in Figs. 11, 12 and 13, includes a va lve disc 44 resting against the valve seat 45 and held in position thereon by a spring 46 whose other end is secured to a plate 41 adapted to be guided by a pair of pins 48 depending from a perforated valve mouth 50 on which is mounted a cam 5| having a handle 52. This handle 52 is provided with an aperture 53 adapted to be aligned with any one of the apertures 54 in the anchor plate 55. By rotating the cam handle 52 about its pivot 56 and placing a pin through the selected anchor aperture 54 and handle aperture 53, the spring plate 41 may be depressed by the cam 5| to place any desired pressure against the valve disc 44. This valve is intended to permit any excess pressure to escape from the breathing apparatus when used as a closed system, it being intended that valve shall be so set that a greater volume of oxygen is released from the bottle, 23 than can be utilized by the user and absorbed as carbon dioxide by the absorbent 33.

'I'he T-pipe 2| includes a nozzle 51 pointing from the oxygen regulator 22 past the exit 49 from the canister 20 to a Venturi tube leading to the breathing .bag I. Obviously, oxygen passing to this Venturi tube 59 creates a suction ln the exit 49 and thus tends to draw the exhaled breath from the expiratory tube I1 through the cartridge 32 and exit 49 to the breathing bag II within its housing I2.

In operation. the user mounts the mask I3 on his face with both tubes connected in operative position as shown, the bag I I being within the housing I2. Access thereto is had, if necessary, by means of the doors 58 on either side thereof. He has but to adjust the control valve 25 to the desired position and thereafter, using it as a closed system, no further attention is necessary unless he temporarily exerts himself so violently that he must open the valve 25 an additional amount to compensate therefor. When used normally, his expired breath passes from the mask I3 through the tube I1 into the canister 20 and is drawn through the carbon dioxide absorbent 32 by the oxygen mask through the Venturi tube insert 59. 'I'he rea'ction of the carbon dioxide and the absorbent creates suillcient heat in the unabsorbed expiratory breath that it warms up the oxygen sufilciently to prevent freezing and has successfully passed tests at temperatures of 40 F. for periods in excess of two hours. The

' oxygen enriched air then passes to the breathing bag II' and refills this bag II at a faster rate than it is normally consumed by the user through the inspiratory tube 3|. As thus used as a closed system, there is no resistant pressure to the exhalation of the user.

The excess pressure built up by the oxygen will escape through the blow-oil valve 43, the pressure at which it escapes being determined by the setting of the handle 52. Should the carbon dioxide absorbent 33 become saturated, the cartridge 32 may be removed while in use by opening the door 38 and replacing the cartridge. While doing so, however, the valve 28 may be manipulated by its handle 6I) from the normal position connecting the regulator 22 to the T-pipe 2| to the emergency position connecting the regulator 22 to the by-pass conduit 30, thus feeding the oxygen directly to the inspiratory tube 3|. The user thus receives an ample supply of oxygen and needs no manipulation thereof during normal use.

The valve 25 will deliver a measured mass of oxygen over a certain period of time. As the user ascends in an airplane the atmospheric pressure decreases so that this same mass of oxygen has an increased differential pressure over that of the decreasing atmospheric pressure. Accordingly, the nitrogen already within the closed system tends to rinse out through the blow-01T valve 43 alongv with some oi the excess oxygen, thus tending to decrease the amount of nitrogen present andI correspondingly increase the proportion of oxygen present so that the necessary mass of oxygen is available for the user in spite of a decreasing atmospheric pressure at which it may be used. As thus used, the oxygen soon tends to rinse out all the nitrogen present, soon permitting the user to be breathing an atmosphere o1' almost pure oxygen which is essential at great altitudes such as thirty thousand to forty-five thousand feet, for which it has been satisfactorily tested.

By proper manipulation of the blow-0H valve 43 and the oxygen valve 25 for a particular altitude, the proper amount of oxygen will always be available for the user. As has already been stated, the carbon dioxide passing into the absorbent generates heat. This heat not only warms the oxygen and prevents it from freezing, but also serves to warm the blow-oif valve 43 and keep it in operative condition at al1 temperatures and pressures.

Should it be desirable to insure that none oi' the exhaled breath should accidentally pass through the inspiratory tube 3|, a check valve 6I may be provided, as shown in Fig. 7, between the inspiratory tube 3| and the bag II and another check valve 52, if desired, may be inserted within a second exit 53 connecting the canister 32 to the T-pipe 2| below the Venturi insert 59. A by-pass valve 84 and 'by-pass conduit 65 may also be provided with the check valve 6I.

Should it be desired to use this breathing apparatus as an open system, then the cartridge 32 may be omitted and the tube il likewise be omitted, as shown in Fig. 6. In this case a regulating air intake valve 86 is secured on the bayonet joint t8. This air intake valve 65, as shown in Figs. 8 and 10, is provided with a rotatable cam 'l having a plurality of graduated apertures S8 which may be selectablyplaced over the valve aperture E9, thus regulating the intake of air through the empty canister Z-.leading to the T-pipe 2l and Venturi insert 5t. Proper setting of this valve 66 and oxygen valve 25 will enable this device to be thus used in an open system as thus described.

Other modifications and changes in the proportions and arrangement of the parts may be made by those skilled in the art Without departing from the nature of the invention within the scope of what is hereinafter claimed.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

Having thus set forth and disclosed the nature of this invention, what is claimed is:

l. A breathing apparatus including an oxygen supply bottle, a breathing bag, a breath purifying device, a mask, a pipe connecting said breathing. bag to the mask, a second pipe connecting said mask to said purifying device, a T-pipe connecting said oxygen bottle across said purifying device to said breathing bag, said purifying device being of a nature that generates heat in its operation, said T-pipe being secured to said purifying device and conducting the generated heat therefrom to Warm the oxygen as it passes therethrough to the breathing bag, and a relief valve on said purifying device, said relief valve being warmed by said purifying device and thereby kept from freezing' when used in an atmosphere of 10W temperature.

2. A breathing apparatus including an oxygen supply bottle, a breathing bag, a breath purifying device, a mask, a pipe connecting said breathing bag to the mask, a second pipe connecting said mask to said purifying device, a T-pipe connecting said oxygen bottle across said purifying device to said breathing bag, said purifying device being of a nature that generates heat in its operation, said T-pipe being secured to said purifying device and conducting the generated heat therefrom to warm the oxygen as it passes therethrough to the breathing bag, an adjustable relief valve on said purifying device, said relief valve being warmed by said purifying device and thereby kept from freezing when used in an atmosphere of low temperature, and means for setting and maintaining said relief valve at a desired adjustment.

HENRY H. FRYE. ALBERT R. BEHNKE. 

